Dielectric material layers are essential components in integrated circuitry capacitors, and are typically interposed between two capacitor plates. Capacitors are used in memory circuits, such as dynamic random access memory (DRAM) arrays.
As device dimensions continue to shrink, an important emphasis is placed on maintaining, and in some instances, increasing a capacitor's ability to store a desirable charge. For example, a capacitor's charge storage capability can be increased by making the capacitor dielectric thinner, by using an insulator with a larger dielectric constant, or by increasing the area of the capacitor. Increasing the area of a capacitor is undesirable because the industry emphasis is on reducing overall device dimensions. On the other hand, providing a thinner capacitor dielectric layer and/or using an insulator with a larger dielectric constant can present problems associated with current leakage, such as that which can be caused by Fowler-Nordheim Tunneling. Current leakage can significantly adversely impact the ability of a capacitor to store a charge.
This invention grew out of needs associated with providing methods of forming dielectric layers having sufficiently high dielectric constants. This invention also grew out of needs associated with providing methods of forming capacitor constructions which have desirable charge storage characteristics, and reduced current leakage.